The present invention relates in general to the field of utility meters. More particularly, the present invention relates to automatic equipment and systems used for remote reading of utility meters, such as electric, gas, or water meters, via telephone lines and modems. Even more particularly, the present invention relates to a method and apparatus for detecting a power outage to a meter and its modem, and reporting the outage to a central office.
The recent deregulation of the utility industry has created a market for products that facilitate the efficient distribution and monitoring of electrical power. In the past, utilities have built systems that worked in a coordinated but independent fashion, and did not provide easy access to certain information necessary to adequately monitor and control a substation, or multiple substations, and related feeder networks and the like from a central location. (Electrical distribution substations and the equipment used therein, such as transformers, circuit breakers, disconnect switches, etc., are well known. See, e.g., U.S. Pat. No. 5,648,888, Jul. 15, 1997, titled xe2x80x9cPower Distribution Substation,xe2x80x9d for background information regarding such substations.) For example, separate devices have been used to monitor a power system to determine when an event, such as loss of power, reduction in supplied voltage, distortion of the voltage or current waveform, or the like, has occurred on the system. One reason to monitor power outage is economic, e.g., power outage will affect equipment and processes and can result in misoperation and damage of equipment, disruption of operations, and other such anomalies. Moreover, with deregulation, many different companies provide power. A consumer, such as a business, may now be able to choose its utility provider, and therefore the customer may now have a need or desire to determine the reliability of the power supplied by its present supplier. Similarly, the utilities have a need to monitor the power they supply to customers to ensure that they are reliably providing power to retain their customers. The sooner a company knows about an outage, the sooner it can be fixed. This provides a competitive advantage. Furthermore, the utilities have a need to localize a fault location in order to determine at what point on a line the power outage has occurred. Therefore, utilities and consumers are now in need of systems to coordinate functionality, such as power quality monitoring, through a network. One aspect of the present invention concerns a system for enabling a utility or one of its customers (such as a large consumer of power) to detect and be notified of a power outage.
Although the art of meter reading via modems and telephone lines is well developed, there remain some problems inherent in this technology, particularly with respect to detecting and reporting a power outage. Therefore, a need exists for a method and apparatus for detecting and reporting a power outage that overcomes the drawbacks of the prior art.
The present invention is directed to an energy meter comprising: a modem having a modem power supply and a modem microcontroller; a power supply for the energy meter coupled to the modem power supply; a battery coupled to the modem power supply; and a telecommunications interface coupled to the modem.
According to one aspect of the present invention, the modem microcontroller monitors the status of the power supply to the energy meter.
In accordance with an aspect of the present invention, the modem microcontroller switches the modem power supply to the battery when the power supply for the energy meter is out.
In accordance with a further aspect of the present invention, the modem microcontroller places an outage reporting call via the telecommunications interface when the power supply for the energy meter is out. The outage reporting call reports outage data comprising an identification, a date, and a time when the power supply for the energy meter is out.
In accordance with a further aspect of the present invention, the meter further comprises off-hook and intrusion detection means for determining the state of a telephone line prior to and during calls.
In accordance with a further aspect of the present invention, the meter further comprises a timer for timing a duration of a power outage.
In a further embodiment within the scope of the present invention, an apparatus is provided for reporting a power outage at an energy meter to a remote site. The apparatus comprises: a modem having a modem power supply and a modem microcontroller; a battery coupled to the modem power supply; and a telecommunications interface coupled to the modem.
Another embodiment within the scope of this invention includes a method of transmitting data from an energy meter indicative of a power outage, comprising the steps of: detecting the power outage; powering a modem by a battery; storing outage data; and placing an outage reporting call to a remote site.
According to another aspect of the present invention, the method further comprises the steps of: determining if the outage reporting call was successful; turning off the modem if the outage reporting call was successful; and placing another outage reporting call to the remote site if the outage reporting call was not successful.
According to another aspect of the present invention, the step of placing another outage reporting call is performed if the outage reporting call was not successful and if a number of attempted outage reporting calls does not exceed a predetermined number.
According to another aspect of the present invention, if the number of attempted outage reporting calls exceeds the predetermined number, the modem is turned off and/or disconnected from the battery.
According to another aspect of the present invention, the method further comprises the steps of determining if the power outage is still occurring prior to placing the outage reporting call; determining if the power outage is still occurring after placing the outage reporting call; and turning off the modem if the power outage has ended prior to or after placing the outage reporting call.
According to another aspect of the present invention, the method further comprises the step of waiting a predetermined time before placing the outage reporting call.